The professions of speech pathology and neurology are involved with the assessment of strength and range of movement of various muscle groups. The examination of these muscle groups involves visual perusal and physical manipulation to determine deviations from normal.
This invention deals specifically and only with that portion of the neurological examination conducted by neurologists, or the peripheral oral examination done by speech pathologists which assess the strength of the tongue when protruded. Currently, tongue muscle strength is determined by having a patient push with his tongue against a wooden tongue blade held by the examiner. The examiner then judges, based upon past experience and intrinsic expectations, whether the muscle response is normal, weak or showing definite paresis.
Protrusion and lateralization of the tongue is accomplished mainly by the genioglossus muscle. Inervation of the tongue musculature is through the hypoglossal nerve. Muscle weakness suggests a disturbance or lesion along neural pathways. Individuals demonstrating tongue muscle weakness may have difficulty with the clear articulation of speech, and with swallowing.
As a component of many therapy procedures the speech pathologist desires to improve tongue strength and mobility as much as possible. This procedure is used with patients who suffer from some acquired neurological disorder, and also children and adults with cerebral palsy, individuals who habitually use a tongue thrust swallowing pattern, and occasionally with "simple" articulation cases where muscle weakness appears to interfere with therapy progress.
To increase muscle strength, isometric-type exercise is utilized. Patients push against a wooden tongue blade that they hold in hand. The strength of the patient produces a variable in the amount of resistance force they are able to sustain when holding the tongue blade. This invention provides a means of taking measurement of tongue strength along an arbitrary scale. The unit is positioned so that the patient is able to push a flexible metal (plastic or wood) blade away from in front of the mouth. The distance the tongue moves the blade indicates the strength of the muscle.
For building tongue strength, the patient uses a wooden tongue blade rather than the metal, or plastic blade. The isometric exercises assigned are performed against a uniform resistance. The amount of resistance can be varied by shifting an abutment member longitudinally of the blade.
Examples of various exercising and diagnostic apparatuses as well as measurement devices including some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 1,363,534, 1,944,601, 1,953,088, 1,976,639, 3,014,286, 3,118,667 and 3,800,782. However, these previously known devices are not specifically designed for exercising the tongue through the arrangement of component parts incorporating a chin rest together with a yieldable structure against which the tongue may be exercised and with the resistance to flexure of the yieldable member being adjustable and the yieldable member having a scale member operatively associated therewith.